For an engineering project for high school, I have chosen to build an automated delivery drone, capable of carrying 1 kg of cargo, in addition to the dropping system we are going to build.
I need help optimizing this build for flight time, flight range, durability, and low cost (under $300 at most).
I think the props need to be large, and motors at low kv, for decreased power draw as a trade off for maneuverability. However, I know little of how to select motors and props and I know there is a lot of complex factors in that choice. This is where I need the most guidance.
I envision a quadcopter being a good choice, but it does not need to be a quadcopter.
As for a transmitter, I will be buying a cheap one, if at all. The drone will be automated, so a controller will only be needed for the initial testing phase and will not be as important once it is up and flying.
Heres my hobby king shopping list:
Quantity Stock Product description Price Weight
4 OK 171000436-0 - NTM Prop Drive 28-30 800KV / 270W Brushl.. $60.20 320
3 OK 017000065 - 12x4.5 SF Props 2pc Standard Rotation/2 .. $13.08 240
5 OK HKz30A - HobbyKing 30A BlueSeries Brushless Speed.. $55.30 235
1 OK HKz-Prog - HobbyKing Programming card for BlueSerie.. $3.28 17
1 OK HK-T6A-M1 - Hobby King 2.4Ghz 6Ch Tx & Rx V2 (Mode 1.. $25.06 998
1 OK FS-L001 - Hobby King 2.4Ghz 6Ch Tx USB Cable $2.85 60
1 OK 015000095 - XT60 to 4 X 3.5mm bullet Multistar ESC P.. $3.36 34
4 OK SHT007 - NTM Prop Drive 2830 Series Replacement Shaft $3.28 52
4 OK NTM28-ACC - NTM Prop Drive 28 Series Accessory Pack $7.40 88
TOTAL: $173.81 2044g
Sky Tools 127 Piece Heat Shrink Tubing Assortment $6.99 1
Vktech 40x 3.5mm Gold-plated Bullet Banana Plug Connector RC Battery $3.99 1
SunFouder 2 pcs Ultrasonic Module HC-SR04 Distance Sensor $8.99 1
NEEWER® Useful HJ MWC X-Mode Alien Multicopter Quadcopter Frame Kit Red/White $16.99 1
Hobbypower Top Pin APM2.6 External Compass APM Flight Controller w/ UBLOX NEO-6M GPS $69.89 1
FTDI Cable 5V VCC-3.3V I/O $17.95 1
Hobbypower Power Module V1.0 for Pixhawk Apm2.5 Apm2.6 Ardupilot Mega Flight Controller $11.101
Neewer Servo Tester CCPM Consistency Master Checker 3CH 4.8-6V $6.95 1
Subtotal (8 items): $142.85
I am going to use a VEX robotics motor to drive the dropping mechanism, they are
reliable geared motors and it will cost me nothing. I will wire voltage from the battery and
servo signal from the APM, they never draw more that 5A so it shouldn't affect anything.
FTDI cable is to set baud rate and name of bluetooth module (JY-MCU slave)
-Can the APM 2.6 take serial input coordinates and route to them? (I am willing to code it myself)
I already have a battery and charger, so that saves ~$60
The Turnigy nano-tech 4500mah 3S 25~50C Lipo Pack is what I already have, and seems like a good choice to maximize flight time to increase delivery range, but is pretty heavy.
I have a mix bag of those little plug wires, and 3 wire ones at the school I can use.
The distance sensors are for collision avoidance, is there any reason not to use those?
-Can I add code to stop and rotate until it is clear of obstruction? We do that in vex with robots, any reason this would be hard on APM?
The frame is inexpensive, if it does break, then we will build a H frame, but I want something to start with.
(also it looks cooler than any welded aluminum frame I could make)
Anything I can cut cost on? $316 subtotal + ~$40 for hobbyking shipping (yikes!) is within the budget.
Anything I forgot?
Thank you for reading my post, if you have any knowledge that can help me succeed in this project, I would love to hear from you.
I agree having a smaller size would be better, what size would you recommend for carrying one kilogram one kilometer away, dropping it, then flying back unburdened, and costing ~$300 to $400?
Do you know if any cheaper flight controllers than the APM 2.6 could support multiple waypoints and low level programmability? We need to fly to GPS coordinate, turn a servo, fly to another, turn a servo, then fly back to home. APM can do that for sure, but at nearly $300, it's way out of budget.
This is hobbyking's APM board, the reviews are positive and it should be able to do everything we need to too, and has telemetry for far less cost that 3DR's package:
All of the parts showed up, put it all together today and took a test flight. It flies easily and deftly. I'll post a youtube video soon.